The velocity of a body upon reaching the point from which it was projected upwards is:

$A$ ball of mass $m$ is thrown vertically upwards. Assume the force of air resistance has magnitude proportional to the velocity,and direction opposite to the velocity. At the highest point,the ball's acceleration is

$A$ ball is dropped vertically from a height of $h$ onto a hard surface. If the ball rebounds from the surface with a fraction $r$ of the speed with which it strikes the latter on each impact,what is the net distance travelled by the ball up to the 10th impact?

$A$ body falls from rest in the gravitational field of the earth. The distance travelled in the fifth second of its motion is ......... $m$ $(g = 10\,m/s^2)$.

An iron block is dropped into a deep well. The sound of the splash is heard after $4.23 \, s$. If the depth of the well is $78.4 \, m$,find the speed of sound in air in $m/s$ $\left(g = 9.8 \, m/s^2\right)$.

$A$ particle is dropped from the top of a tower. The distance covered by it in the last one second is equal to the distance covered by it in the first three seconds. The height of the tower is $....m$